Anatomical studies in progress include: 1) tracing the spinal lemniscal and trigeminal pathway with axonal transport methods using HRP and tritiated amino acids or adenosine. Thalamic, intranuclear and retrograde ganglion cell labelling are being studied in rat and cat with these methods. 2) Freeze-fracture studies of the spinal trigeminal nucleus with emphasis on developing improved cryoprotectant methods for cytoplasm sublimation. 3) Electron microscopic study of delta nociceptor endings in cat skin and development of immuno-labelling techniques for C nociceptor endings. Electrophysiological studies planned include comprehensive modality (and topography) mapping of thalamic ventrobasal nucleus and forelimb zone of SI cortex with quantitatively controlled stimulation of skin. A new series of experiments is planned for quantitative study of directional selectivity in mechanoreceptive neurons from the periphery to cerebral cortex.